Mining machine



J. B. MAVOR MINING MACHINE Aug. 5, 1947.

Filed July 18, 1944 INVENTOR Patented Aug. 5, 1947 MINING MACHINE John Bridie Mavor, Glasgow, Scotland, assignor to Joy Manufacturing Company, Franklin, Pa.

Application July 18, 1944, Serial No. 545,433 In Great Britain July 29, 1943 2 Claims.

A common method of mining coal is to undercut the coal face by means of a coal cutting machine and then to break the coal down by means of explosive. The broken coal is then loaded out from the coal face.

Coal cutting machines of what may be termed the cutter-loader type are known. These machines comprise a cutter element or elements for undercutting and (or) overcutting the coal face and a shearing cutter element which cuts the coal in a plane substantially parallel with the front of the coal face. As a result of these cuts the coal breaks down as the machine progresses along the coal face and the use of explosive is not necessary. Such machines are, however, inclined to be cumbersome and expensive.

The present invention is concerned with a mining machine adapted to make only a shearing cut, i. e. without undercutting or overcutting the face, and then to break the coal away by the action of a head or heads of wedge character forming part of the machine.

According to this invention, a mining machine of the construction just referred to is provided with bursting mechanism comprising parts which can be moved relatively to one another in the transverse direction within the shearing cut so as to exert a direct disruptive force on the coal.

The bursting mechanism may be of fluid pressure type, comprising for example, a series of small pistons arranged to act in the transverse direction. Such mechanism may be carried within the track of an endless shearing cutterchain.

The shearing-cutter and bursting mechanism may be associated with a wedge shaped head or heads adapted to be forced into the shearing out.

An example of construction will now be described with reference to the accompanying drawings, in which:

Figures 1 and 2 are a side view and a plan view showing a mining machine; and Fig. 3 is an enlarged horizontal section through one of the pistons of the bursting mechanism, showing it projecting from the wedge head.

Referring to Figs. 1 and 2 of the drawings, a mining machine I rests on the floor 2 of a coal mine, and is adapted to be skidded forward (to the right) along the floor in a well-known manner. The coal in the mine shown is being mined by the long-wall method, and therefore the seam has a working face 3 in a plane parallel to the path of movement of the mining machine. The rear end of the machine is not shown in the drawings because it is of conventional construction. The central portion of the machine forms a housing 4 for an electric motor, and from this housing the shaft 5 of the motor projects forward into a narrow housing 6. The front end of this shaft carries a beveled pinion 1' which meshes with a beveled gear 8 mounted on a driven shaft 9 journaled in the gear housing. This shaft projects from the inner side of the gear housing and carries a sprocket I0.

Mounted on the front end of the gear housing is a wedge-like head ll of the pronged shape shown. The projecting central portion of this head is rectangular when viewed from the side and forms a burster panel l2. As shown in Fig. 2, the outer surface of the panel is inclined outwardly from its front end to its rear end so that the panel also serves as a wedge member. An endless chain-like shearing cutter or cutter chain I3 extends around sprocket l0 and forward around the front end of the burster panel. This chain is supported and guided by a channelshape track I4 which is supported from the body of the machine in any suitable manner. The chain includes teeth I5 which cut a vertical slot I6 in the coal parallel to the working face 3 as the machine moves forward. The burster panel enters the slot formed by the front of the cutter chain.

The panel I2 is provided with a plurality of chambers 20 (Fig. 3) forming cylinders extending inwardly from the inclined outer face of the panel, six cylinders being shown in Fig. 1. Slidably mounted in each cylinder is a piston 2| which can be forced outwardly a limited distance by fluid pressure. For this purpose an oil tank 22 mounted in the head is connected by a pump 23, driven by a chain 24 from shaft 9, to a pipe 25 that leads to a manually operable valve 26 mounted on a supporting member 2'! between the motor housing and the head. Connected to this valve are three pipes 28, each of which leads to a different pair of the cylinders 20 in the burster panel. The valve, which is of conventional construction, can be manipulated to connect the oil pump with any desired cylinders, or to allow the cylinders to exhaust back through pipes 28 and a pipe 29 to the oil tank. As the panel enters the slot l6 cut by the shearing cutter, the valve is turned by an operator generally to connect the front pair of cylinders with the pump, and then the other two pairs in succession with the pump. The fluid pressure then developed in the cylinders forces the pistons outwardly against the adjoining coal and breaks it away. As the coal breaks down it is scooped 3 up by a shovel 30, which forms part of the head, and is raised by the inclined shovel and discharged laterally.

I claim:

1. In a long wall mining machine a cutter chain positioned to cut a vertical slot in a body of coal substantially parallel to the working face of the coal, a wedge member carried by the machine with the front end of the wedge disposed behind the front of the chain and adapted to enter said slot as the machine moves forward, the outer surface of the wedge being inclined from its front end rearwardly, said wedge member being provided with transversely extending fluid pressure chambers, pistons mounted in said chambers, and means for supplying fluid under pressure to said chambers to force said pistons outwardly toward said Working face and against one side wall of said slot to break the coal away.

2. In a long wall mining machine adapted to travel along a coal face, a kerf cutter positioned to cut a vertical kerf in the coal substantially parallel to its working face but spaced inwardly thereof, a wedge member carried by the machine with the front end of the wedge member disposed behind the front of the kerf cutter and adapted to enter said kerf as the machine moves forward, the outer surface of the wedge member being inclined from its front end rearwardly for applying a lateral pressure to the section of coal between said kerf and working face, and expansible breaker means carried by said wedge member and arranged to act relative thereto against the outer Side wall of said kerf for applying a supplemental breaking down pressure to said section of coal subjected to such lateral wedging pressure, whereby to break the coal away.

JOHN BRIDIE MAVOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,290,020 Levin Dec. 31, 1918 1,741,714 Hughes Dec. 31, 1929 1,809,282 Morgan June 9, 1931 1,824,727 Marion Sept. 22, 1931 2,148,495 Osgood Feb. 28, 1939 FOREIGN PATENTS Number Country Date 501,194 Germany June 28, 1930 

